Why does windows registry of fonts indicate they are all true type?

Question

I'm on Windows 7 Home Edition. This is a screen shot of my registry for HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Fonts.

As you can see, the titles all have "(TrueType)" in them, even tho most in the screen shot are .otf files (Open Type Fonts). There are some .ttf types at the end.

Why is this? I've never modified this part of the registry ever. I've never had a different font with the same name, for Alegreya at least.

Is this a bug of windows? Does the title not even matter at all?

I noticed I could rename those titles without ill effects, but I haven't tried rebooting with it yet. Do I dare try?

Answer 1

It's a backward compatibility thing. Most applications will completely ignore the "Name" column in the Registry and instead they will get the name of the font from the font file itself. You can call them whatever you want in the registry and most apps won't care.

Some much older apps may use the names in the first column, but this registry key is really only there so Windows can enumerate the file names, which it provides when applications request a list of the fonts available to the system, so it's really only the "Data" column that matters.

Answer 2

Because Open Type fonts are True Type fonts, just an extension of the old format. There's no strict border between the two, Open Type practically means a True Type package that uses at least some of the new features that make it useful for better typography.

These newer True Type fonts can describe the character shapes in two different ways, one comes from the older True Type era, using quadratic curves. By convention, these fonts retained the .ttf extension. They can also describe the shapes using cubic curves, based on earlier PostScript (Type 1) fonts, although using a more compact internal representation. By convention, these fonts use the .otf extension.

The extension is only a convention, any font manipulating software worth its salt will recognize both formats internally even if the extensions are mixed up.